The majority of paints used today comprise mixtures of several elements and ingredients, including the liquid paint thinner or vehicle, the color pigment, various thickening agents and certain chemicals included to control the cure or drying rate of the paint. Typically, the ingredients in such paints include materials which are liquid and materials which are solid particulate matter suspended in the liquid components of the paint. As a result of the combination of such a variety of elements within typical paint mixtures and the provision for curing or drying of such paint mixtures, there is a tendency, in even the finest quality paints, for lumps or collections of partially cured or solidified particulate matter to form within the paint during processing and storage time. In addition, the presence of impurities and foreign material within such paints produces further inconsistency of texture and often contributes lumps or solid objects within the paint. Further, and particularly in connection with paints used in outdoor applications, contaminants often find their way to the paint in the form of dirt and other typical outdoor contaminants to provide a further accumulation of bits and pieces of foreign material within the paint mixture during use.
As a result, painters often contend with inconsistencies, foreign materials and partially solidified lumps or other variations of texture in the paint which they apply. In applications of such paint utilizing the common devices, such as brushes, rollers or paint pads, the presence of such inconsistencies, foreign materials and lumps is a nuisance and sometimes requires removal from the painted surface but can, in most cases, be dealt with by the careful painter.
However, in recent years, a substantial number of painters, particularly those operating in the painting of houses or other dwelling structures, have opted to utilize paint spraying devices to cover the majority of large painted areas. For example, residential and commercial building painters often spray the majority of surfaces to be painted leaving touch-up and trim portion to be covered using more conventional brush and roller techniques.
While many types of spray painting apparatus have been developed through the years to meet the needs of painters, the most common includes the basic system components of an air compressor, a spray gun, a paint reservoir and a plurality of interconnecting hoses. The basic system function provides that air pressure from the compressor is utilized to drive the paint through the spray gun. In some systems, the paint and compressed air are joined at the spray gun in what amounts to a siphon feed action operation in which air passing through the spray gun draws paint through a connecting hose between the spray gun and the paint reservoir. In other systems, the paint is transferred from a reservoir to a pressurized chamber pumped with sufficient pressure to drive the paint under through the spray gun and onto the painted surface.
While such paint sprayers offer a substantial increase in speed and quality of painting attainable by painters, the spray guns themselves contain relatively small paint passages and nozzle orifices and are therefore extremely sensitive to being clogged by particles, foreign matter and lumps within the paint. In most situations, a clogged gun must be immediately removed from the system and completely or partially disassembled or otherwise cleaned and freed of the clogging material before the painting operation may be resumed. As can be imagined, the need to frequently interrupt the painting process to clean a clogged spray gun or associated spraying apparatus is time consuming and costly to the painters.
As a result of the problems caused by clogged spray guns, the practitioners in the painting art have adopted the use of various paint straining devices with the object of preventing clogging particulate matter and lumps from reaching the sensitive spray gun. The most common paint sprayer in use among commercial painters comprise a flexible mesh filter bag which is positioned over the top of the paint reservoir and allowed to sag or extend downwardly into the reservoir while having its remaining portion draped over the reservoir sides. Paint is then poured through the paint strainer into the reservoir before use. Once the remainder of paint has passed through the strainer bag, the strainer is lifted by its sides and the residual of paint is squeezed through the paint strainer by the painters hand squeezing action. Thereafter, the strainer bag and any accumulated lumps or particles which have been filtered out by the straining process are disposed of.
While this method of straining does remove the majority of particulate matter and lumps from the paint to be used, its use is inconvenient, time consuming and messy, leading to the situation where the majority of painters simply do not like to use such strainers. As a result of the extent of painter's dislike for using the above-described strainers, some often elect to avoid the paint straining operation entirely and assume the risk of a clogged spray gun.
There remains therefore a need in the art for an effective, convenient, clean and easy to use paint strainer which avoids the foregoing described problems.